Clutch start safety question- need your opinion

Discussion in 'U-shift em' started by CJay, Nov 18, 2018.

  1. CJay

    CJay Supercar owner Staff Member

    So I was talking to a friend of mine and tells me that he jumped out the clutch safety switch on his 4 speed car so he can start his car up without pressing the clutch down. When I asked him why, he said that pushing the clutch in when starting the car puts excessive wear on the thrust bearing. His thinking is that there is a few seconds where the engine is getting pushed forward against the thrust with no oil pressure.

    Now he's got me thinking I should bypass the switch? Does he have a point? Wouldn't that theory be true of all the bearings? Of the whole engine really? I mean, there is a few seconds there where you cranking until the pressure comes up. Ive been driving 4 speed cars for years. Never had an issue. What say you? Will it ultimately extend the longevity of the engine? Or should I just shrug it off as the rantings of a lunatic? :D
     
  2. moleary

    moleary GOD Bless America

    Clutch in = no load on engine. I am sorry if I’m being dense but I don’t get it. The pressure from depressing clutch against flywheel? FYI I jumped down my wires as I am using my OEM clutch switch for my two step Mallory launch...
     
  3. CJay

    CJay Supercar owner Staff Member

    Whats he's saying is when you push in the clutch, your pushing the crank forward up against the thrust surface of the #3 bearing
     
  4. moleary

    moleary GOD Bless America

    Right. I can’t imagine that light pressure would erode that bearings life as it sees so much more abuse durring driving especially how we drive
     
  5. wkillgs

    wkillgs Gold Level Contributor

    I worry about the dry pressure too, but probably not a big deal.
    The safety lockout is a good idea, but keeps you from doing 'starter races'! I have a friend who liked to do that and he broke a chunk of the block off of his 4 speed 396 Caprice.
    I once broke the clutch linkage in my '67 Fairlane 289 4 speed. To drive it home, I had to leave it in gear to crank and start the engine.

    If you do remove the safety, just be absolutely sure to have it in neutral when starting. Using the e-brake would be a good habit too. You don't want to crank it while in gear with clutch out, it could happen.
     
  6. CJay

    CJay Supercar owner Staff Member

    Starter races.....LOL! I broke the ball stud off the block on my 442 years ago. Drove it home in 3rd gear, that was fun:rolleyes:

    You bring up a good point, brain farting and cranking the thing in gear. All you need is one lapse and your out a bumper
     
  7. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Any thought of premature thrust wear is kookie talk...
     
  8. wkillgs

    wkillgs Gold Level Contributor

    Or a garage door! In my youth, one of the guys ( 14 y/o) cranked over his brothers 67 Stang and put it into the garage door.
     
  9. bignastyGS

    bignastyGS Maggot pilot

    I believe they are a good idea.I even installed the switch on both the cars I swapped from auto to manual. They were used for a reason.I don't buy the damage idea..I was harder wailing through the gears on the motor that I ever done by starting it with the clutch in..
     
  10. CJay

    CJay Supercar owner Staff Member

    And incredibly, Ford never installed a safety switch on early Mustangs. Jen's 73 has no switch. So odd
     
  11. 69GS430/TKX

    69GS430/TKX Silver Level contributor

    The switch on my 69 had already been disabled when I bought it, so I have left it that way. It had a very strong clutch, and every time the pedal was depressed it shortened the life of the linkage and also the life of my left knee! So it was nice to just put in neutral and turn the key. Also nice if you parked on a hill and your e-brake doesn't work. To start engine, you need one foot to hold the brake pedal so car doesn't roll, one foot to pump the gas pedal. That leaves you one foot short for depressing the clutch.

    Plus, what if you are parked or stalled (vapor-locked or out of gas) on the train tracks, and a train is coming? Nice to be able to just let that starter motor crawl you to safety. Okay, that's unlikely.
     
  12. moleary

    moleary GOD Bless America

    I am planning to split the circuit so the NS works and the two step trigger...I do like being able to start engine from outside....
     
  13. BillA

    BillA Well-Known Member

    I'd somehow rig up a neutral safety switch prior to disconnecting the clutch safety switch if you decide to go that route. You mention one lapse and you're out a bumper. One lapse and some poor soul standing in front of the car may be out a pair of legs.
     
  14. sriley531

    sriley531 Excommunicado

    No switch on the green car. Since I'm the only one that drives it, I decided not to put one on. In all the insane amount of tinkering I've done on that car, it's too nice to reach in the window and bump the key and have it fire. That said, there was one incident where the key was hot with it in gear, and that was by the only person other than me to ever drive it. But it's so rare that anyone else is starting it, I'll take the chance. If I ever sold it id probably out one on prior.
     
  15. BadBrad

    BadBrad Got 4-speed?

    Mine was jumpered by the original owner; don't know why. But he was a mechanic of mechanics; taught diesel technology at Stanford back in the old days. He did use this car to tow his large boat and perhaps that had something to do with his decision.
     
  16. 87GN_70GS

    87GN_70GS Well-Known Member

    Came in handy once when I ran out of gas at a stop light. When the light changed, I rode the starter across the intersection, shifting once, and pulled up to the gas station. Got a few funny looks!
     
  17. BUICKRAT

    BUICKRAT Got any treats?

    Leave it connected...I could tell you some stories, and none ended well, about folks who disconnected them.
     
  18. moleary

    moleary GOD Bless America

    Interim, you can wire a heavy duty toggle bypass in and hide under dash so it serves as security anti theft measure and a deliberate second stop to not start in get without thought....
     

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